A composite material blade including a part forming the blade foot for the connection to driving means and an aerodynamically profiled main blade section is known, particularly from U.S. Pat. No. 6,035,531, which is incorporated by reference herein, said main blade section comprising at least one casing cover and two spars extending along the span of the blade and each located against the casing cover, one against the intrados side and the other against the extrados side of the blade, the spars extending into the part forming the blade foot, the part forming the blade foot including anchoring reinforcements located on either side of each spar.
The blade of the above mentioned type is obtained by the molding process commonly called Resin Transfer Molding or RTM.
Even if this molding technique enables the making, at moderate cost, of a blade having an excellent surface state coming out of the mold, so that very little touching up is necessary before this blade is painted, it is still necessary to improve its mechanical behavior, particularly in the spar, and to reduce the number of cut-outs in the covering and in the blade attachment zone.